Thirty minutes of exercise is enough for weight loss

Less may be more when it comes to exercising to lose weight.

A new study finds that a half-hour workout works just as well as an hour of exercise to help overweight men shed pounds.

Researchers at the University of Copenhagen conducted a study on 60 moderately overweight Danish men to test how much exercise was needed to kick-start weight loss.

They had a third of the men exercise hard enough on a treadmill or bike to break a sweat for 30 minutes a day; another third did an hour of exercise a day, while the last group did no exercise.

The researchers found that the first group lost an average of 8 pounds over 13 weeks, compared to an average weight loss of 6 pounds among men who worked out for 60 minutes a day. The results appear in the American Journal of Physiology.

The researchers say their results were surprising even to them, but they say it may be that the men in the first group found 30 minutes of exercise easier to manage and had extra energy left over for more physical activity during the rest of the day.

Or it could be that the group that spent 60 minutes on the treadmill were hungrier after their workouts and ate more, and therefore lost slightly less weight than anticipated.

The researchers found that the men who exercised 30 minutes a day actually burned more calories than they should have according to their exercise program.

Meanwhile, the men who exercised 60 minutes a day lost less body weight relative to how much energy they burned during their workouts.

Guidelines from the Canadian Society for Exercise Physiology advise adults to get 150 minutes (or 2.5 hours) of moderate- to vigorous- intensity physical activity a week, and 60 minutes a day for children and youth, ages 5 to 17, to promote good health.